1. Technical Field of the Invention
The present invention relates to a method and apparatus for reconditioning worn openings in roller conveyor side frames.
2. Description of Related Art
Roller conveyor systems typically mount a series of conveyor rollers between two parallel, longitudinally extending, side frames. The rollers comprise an outer tubular covering with a bearing mounted shaft (axle) running through the middle of the roller and extending out past each roller end by several inches. Holes, slots, apertures or cut-outs (generally referred to as openings) are provided in each side frame, and the extending ends of the conveyor roller shafts are inserted in, and retained by, opposed pairs of such openings in the parallel side frames. The rollers may then be actuated through an appropriately configured drive system (such as a motor driven belt or chain drive).
When a roller conveyor has been in use for a number of years, the side frame openings which receive and retain the conveyor roller shafts (axles) can become distorted. Repetitive back and forth actuation of the conveyor roller causes the shaft of the roller to twist back and forth in the shaft opening of the side frame. Over a period of time, this twisting action tends to wear away at or distort the shape of the shaft opening. For example, with hexagonal shaft openings and correspondingly shaped conveyor roller shafts, the twisting action will, over time, turn the hexagonally shaped opening into a circularly shaped opening. It is also possible, although less likely, for such wear to turn a hexagonally shaped shaft into a round shaft. In either case, at this point, the shaft is free to rotate or spin within the opening which adversely affects conveyor operation.
This problem, however, is not the only concern experienced with such wear. As the hexagonal opening initially begins to wear, this allows for more movement (twisting) of the shaft which results in an increased noise level (rattling) caused by metal-to-metal contact of the shaft against the frame. This contact further increases the vibration effects experienced with operation of the roller conveyor, with the increased vibration possibly leading to premature failure of other conveyor components.
The most common solution to this problem is, unfortunately, an expensive and inconvenient solution. In many situations the side frames of the roller conveyor system must be replaced. Additionally, it is recognized that side frame failures of the kind discussed above, along with the resulting collateral adverse vibratory effects of such failures, may necessitate complete replacement of the roller conveyor system. It is still further recognized that many businesses which utilize and rely on conveyor systems cannot afford the downtime typically associated with large scale conveyor repair or replacement tasks. Thus, given the significant capital expenditures involved in purchasing and installing roller conveyor systems, and further recognizing the large number of such systems already installed and in continuous operation, there is a need for a quick, easy and inexpensive device and method for reconditioning and/or repairing conveyor side frames to retain roller conveyor shafts.
A shaft capturing device useful for reconditioning worn roller conveyor side frame openings includes a base portion and a flange portion. An opening in the flange portion is sized to receive a roller conveyor shaft. A mounting opening located in the base portion accepts a mounting screw that when tightened pushes against and engages the roller conveyor side frame causing the base portion to move away from the side frame and the opening in the flange portion closes in size to tighten around the received shaft.
In an embodiment of the invention, the device is shaped to taper and narrow in its depth dimension from the base portion toward the flange portion.
In another embodiment of the invention, a slot is formed passing through the flange portion shaft receiving opening to define a pair of clamping tangs. An opening extending through the tangs accepts a screw that when tightened pulls the tangs together to clamp the tangs of flange portion to the received shaft.
In yet another embodiment of the invention, the flange portion includes multiple shaft receiving openings spaced apart with a pitch substantially matching that of plural adjacent openings located in the conveyor side frame.
In yet another embodiment, the shaft capturing device may be used on new (or newer) roller conveyors in an effort to prevent wear or allow for incompatibly sized and/or shaped side frame openings and roller shafts to be used.
In yet another embodiment, a friction device may be included in with the shaft receiving opening to further restra against efforts to axially displace the device from the roller shaft.